Summary
3D printing is cool. Learning to design your own models is the best way to take full advantage of 3D printing today. This book will teach 3D modeling by a series of hands-on activities so it's a good idea not to skip and actually follow along with each blueprint.
While home 3D printers have the capability to do break away supports these are messy and wasteful. It is possible to design things to be able to print without the need of any supports. When designing things for support-less 3D prints remember Y prints, H prints okay, T does not print. Keep outward inclines gradual and no more than 45 degrees to be safe.
There are many 3D modeling programs to choose from. Some are expensive, some are free. Some are better for technical works, others do artistic or organic shapes better. Some are easy to learn, some take more practice. This book will use Blender since it is free and open source, has tools for modeling technical and organic shapes and is not too difficult to learn if you learn by doing.
Blender can be a bit tricky to get started with since it employs some conventions unique to its environment. Blender can be customized but this book will stick with the defaults so everyone is on the same page. Generally remember that Ctrl + Z undoes a multiple mistakes and can get Blender back to the state it was before, useful in tutorials to get back on track. The location of the mouse pointer is important when using Blender's hotkeys, which is the best way to learn to use Blender. Blender uses the right-click on mouse for selection by default. Finally, Blender's units translate to real life by 1 Blender grid space = 1 millimeter.
The next chapter will be a proper tutorial, teaching the most common modeling tools in Blender by inserting common shapes and manipulating them to the desired shape. Then that shape will be automatically smoothed to make it more appealing. Finally, the model will be edited and prepared for printing, utilizing the rules taught in this chapter.